A long sought objective in the amplifier art has been to obtain a power amplifier having a higher efficiency of power consumption. Therefore, power amplifiers have been provided with a switching regulator as a power supply means in recent years. The switching regulator has higher efficiency of power consumption and occupies less space than conventional series regulator type power supply means. The switching regulator, however, has a shortcoming in that it has high frequency ripple components in the output current.
As a result, the power amplifier driven by the switching regulator is apt to have undesired radiation resulting from the amplified high frequency ripple components of the output of the power amplifier. Furthermore, the output signal from the power amplifier is distorted by the high frequency ripple components.